agreed - trading a daughter away should have a amount of coins depending on the factions power level that the daughter is leaving.

I would agree.

But what I would rather see would be the dynasty system working as advertised.

You trade your child away because they get a place in the line of succession. Meaning if you kill everybody above them, you then take control of the other kingdom.

I'd prefer to see it even just as a way to differentiate factions. Some cultures like the dude to live with the family. Some like to get their daughters the hell out of the house. Some factions could just prefer marriages where they gain people rather than when they have to give them away, or vicea versa.

It should be part of the deal, to decide whether its the son of the daughter that leaves to marry out. Right now, all my sons get married and my daughters never do.

I belive there should be some compensation for loosing a daughter, if not a cash dowry, maybe double the political bonus.

As a side note on the matter of dynasties, what's the point of listing "Nth in line for the throne of (you/them)" if ownership of the faction cannot change hands?  It would be very interesting to be able to shift the game from Player = Soverign to Player = Soverign's bloodline.  The player controlling the "1st in line" takes control of the faction.  Cities, units, treasury, everything.   A dynasty is a lineage of hereditary succession, not just a baby machine.